Safety device for presses.



F. GRAFFENBERGER.

SAFETY DEVICE FOR PRESSES.

APPLICATION FILED JUNE 20, 1914.

1,138,374. I Patented May 4, 1915.

a SHEETS-SHEET 1.

F. GRAFFENBERGER.

SAFETY DEVICE FOR PRESSES.

APPLICATION FILED JUNE 20, 1914.

, Patented May 4, 1915.

3 $HEETSSHEET 2 IE1? em to x I" I, I

- attorney;

Inventor.

F. G RAFFENBERGER. SAFETY DEVICE FOR PRESSES. APPLICATION FILED JUNE 20. 1914.

Patented May 4, 1915.

3 SHEETS-SHEET 3 10 FIIIIIE FEED-752066366 Era I connection with a corner staying machine for: applying gummed. stays or strips to the fluent and combination of partsfas herein- UNITED STATES PATEN OFFICE- FRIEDRICI-I. 'OdiIAFFENBERGER, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO A. GEO. SCHULZ CO.,'OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

SAFETY DEVICE FOR PRESSES.

Specification of Letters Patent.

Patented May 4, 1915.

Application filed June 20, 1914. Serial No. 846,240.

lar machines in which the work is pressed or acted upon by dies one of which is movable toward and from the other. -It is shown for the purpose of illustration in corners of pasteboard or paper boxes, al-

'though it is applicable to machines having reciprocating tools or parts for performing other operations.

The main objects of the invention are to prevent crushing or injuring the fingers of operatives employed in feeding such machines and to avoid mutiliating and spoiling work improperly placed between the dies or presented to the tools without interfering with the rapid an most eliicient operation of,. the machines.

. It consists in the construction, arrangef after particularly described and pointed out .eral v v Figure 1 is a side elevation and vertical .section on the line 1-1, F 1g. 2, of a portion in the claims. In the accompanying drawing likechar- ,35

acters designate the same parts in the sevfigures.

,Lof a corner-staying machine embodying the invention; Fig. 2 is a front elevation thereof; Fig. 3 is a front elevation and longitudinal section of the pitman on the line 3-3, Fig.4, showing the parts of the pitman in -;nor1nal working condition; Fig. 4: is a "x fr-opt elevation similar to Fig. 2, showing the parts in different positions; and Fig. 5

.is a front elevation and section similar to Fig. 3, showing the parts of the pitman in the positions they assume when the movable present invention are rsh'own, comprisesjia vertically reciprocating head 1, guided between parallel ways 2, a die 3, adjustably and detachably connected with the lower end of thehead, an anvil or stationary die 4-, adj nstably and detachablyconnected with the frame of the machine below the die 3 and a crank or eccentric 5, mounted on the front end of a. horizontal shaft 6, which is supported in bearings in the upper part of themachine frame, and has a suitable clutch controlled driving connection "(not shown).

The head 1 has a longitudinally movable block 7, fitted and guided in a recess in the rear side of the head and provided with a rearwardly projecting wrist pin 8. A eylindrical stem 9, having an adjustable threaded connection with the upper end of 12- encircles, the stem, bearing at its lower end against the head and at its upper end against a washer 13, which is seated against a shoulder formed on the stem by the enlargement of its upper end The movable die 8, which is rigidly secured to the lower end .of the head 1, is thus permitted to yield upmardly with the head When it is forced by the eccentric 5 downwardly upon work held on the anvil or stationary die 4, in applying gummed stay strips to thecormore of boxes. The stem 9.1aflords means for adjusting the die 3 vertically relative to its driving connection and the anvil 4 to vary the pressure and'properly operate on .stock of different kinds and thicknesses. 'A knife or cutter is, fastened to the frame of the machine at the rear end of the die 3 above the anvil 4, is formediwith an in verted V-shaped cutting edgej fc'orresponding with the die and anvil for cooperating with the dieto sever the stayjstrigwhich is showh'in Figsfl and 2. Thedieiiiis se in place in a socket in the head: 1' screw slt-fwhi'chrserves also to" adj ust the rea-r end '100 fed by means not shown,over --a 'guide l5 1 through an opening in the knife between the die and anvil when they 'arei separated, as eured= 1'05 '40 is fitted and adapted opening in the latch of the die so that it will work properly with the knife 14;.

As thus far described the machine is of well known construction and no claim is made thereto per se.

I For actuating the head 1 with the die 3, the eccentric 5 is connected with the wrist pin 8 by a pitnian 17, to prevent crushing and in uring the lingers of operatives and-to avoid mutilating and spoiling worlr misplaced on the anvil 4:, the pitinan has yielding connection with one of the connected thereby, and pr fer con structed as follows, and as shown detail in Figs. 1, 3 and 5. At its end it is formed with a head or cy n-turical bearing fitting the wrist pin 8, and its upper end with a longitudinall slotted strap head ting the upper side of the eccentric or crank pin 5. A bearing piece 18, tit-ting the lower side of the eccentric or crank pin 5, is fitted and guided in the slotted head and movable lengthwise of the pitinan. The beari g piece 18 is formed or provided with a stem 19, preferably square, which is loosely fitted and guided in a longitudinal socket or hole formed therefor in the pitman. For con- 'venience of construction, the socket or hole for the stem 19 preferably extends through the opposite end of the pitinan. The bearing piece 18 is yieldingly held against the eccentric or crank pin 5 by a spring 20 inserted in the hole or socket oi the pitinan and bearing at one end against the inner end of the stem 19 and at the opposite end against a block 21 fitted to the wrist pin 8. On one side the stem 19 is cut away to form a notch or shoulder 22, and in a transverse opening in'the pitman 17 a latch 23 when thrust inward to engage with the shoulder 22 and lock the bearing piece 18 in its normal working position in which it is shown. in Fig. 3. A cam lever 24:, fulcruined atits lower end in a longitudinal groove or recess in one side of the pitman 17, projects at its upper end into an 23, in which it has a limited amount of play. A spring 25, held in a socket in the side of the pitman 17 and hearing at its outer end against the inner side of the lever2 l, holds the latch normally in its retracted or inoperative position, as shown in Fig. 3, leaving the bearing piece 18 free te-yield toward the wrist pin Cm its outer side the lever 2% is formed with a projection 2-6, and in the path of thi's'projection an adjustable abutment '2'? is attached "to the frame of the machine in position to thrust the latch 23 inward when the die 3' in its downward orladvance movementlis within a certain distance of the anvil i. ThlS abutment 27 may be conveniently in the form of an eccentric having a cylindrical stem passing through a transverse holem one side of the frame and secured compensates for variation in the throw of the lever due to change in the adjustment of the abutment 27, and permits any excess movement of the lever beyond that required to properly engage the latch with the shoulder without causing the latch to bind on the stem 19, or subjecting the lever and connected parts to injurious strains. .The pitman thus constructed constitutes a yielding connection between the eccentric or cranli'pin 5 and the wrist pin' S, and in connection with the latch 93, lever 2-1 and abutment 2?, will, when properly adjusted, prevent crushing the fingers of operatives, but

will not alone prevent bruising the fingers if they are caught between the die and anvil, or prevent mutilating and spoiling work improperly placed on the anvil, since the fingers or work under these conditions will be subjected to the weight and impact of the descending head 1 and pressure of the spring 20.

.To prevent bruising or hurting the fin era of operatives and mutilating and spoi ing work, the machine is further equipped with means for arresting the downward or advance movement of the die and the head to which it is-attached, when an obstruction such as a finger of the operator, or improp erly adjusted work, is placed in the path of the die in such position that it would be crushed or injured by its further advance. To this end the reciprocating head 1 is provided {with a clutch or clutches for clamping or looking it to a stationary part or parts of the machine and with. a guardor guards inovably connected with the head and adapt ed when it meets an obstruction in its path,

to operate the clutch or clutches and arrest further advance of the-head and the die 3, the yielding connection of the pitman with the eccentric or crank pin 5 permitting the eccentric or crank pin to complete its revolution when the advance of the die 3 is thul'" arrested. i The clutching or locking device and the movable guard for operating the same, may

be conveniently constructed and applied to a corner staying machine of the character shown, as follows: A plate or block 29, attached to the front side of the head 1, is

' formed in the ends overhanging the ways 2,

with pockets 30, having upwardly and outing inclined projections 33 on their inner sides in the paths of the rollers 31 when the latter arelifted as hereinafter explained and asshown in Fig. 4, into the upper narrower portiono'f the pockets 3'0. L-shaped guards parallel with the die 3. The upwardly eX- 3%, whi ii may be made of comparatively light Sheet metal, are inovably connected wi h no front face of the plate or block 29, and, a. similar plate or 'block 3?, attached to th headl below nd at a distance from the ate or block by screws 36, threaded in 2ndpl'ates' or blocks and passing loosely through vertical slots in the guards, the screwsbeing provided next to their heads with washers, which are spaced from said plates or blocks and prevented from binding against the guards by oblong washers'37, as shown in Fig. 4:. At their lower ends the guards, which project inwardly toward each other, as shown in 2 811C141, are formed or provided as shown in Fig. 1, with rear wardly pro ecting arms 38, ad acent to and tending vertical members of the guards overlie the pockets 30 and confine the rollers 31 therein. A cross bar 39 is adjustably at tached adjacent to its ends to the vertical members of the guards between the plates 29 and 35 by screws 10, threaded in said bar and passing through vertical slots in the guards. The guards thus connected with each other and made to operate as one. Light spiral springs 41., seated in sockets formed in the upper side otthe bar 39, adjacent .to its ends, pass upwardly and are loosely guided in vertical openings through the plate 29 into the, lower ends of the pockets 30 and are adapted to elevate the rollers 31rin said pockets when the downward movement of the guards is arrested by an obstruction.

In the operation of the machine equipped with safety devices as hereinbefore described, the abutment 27 being adjusted to lock the yielding bearing piece 18 in its normal wor ring position, in which it is shown in Fig. 3 just bet'orethe die 3 in its downward movement comes into contact with a box corner held on the anvil 4, the further downward or advance movement of the die positively presses a gummed stay which has been fed forward between the die and anvil and cut to the required length by 'the die and knife 14, against the box corner on the anvil. In case the operator inadvertently thrusts a finger into the path of the descending die either from the front or side while the die is far enough above the anvil to admit of the insertion of a finger between them and before the projection 26 on the lever 24 has descended v tar enough to encounter the abutment 27 and lock the bearing piece 18 in its normal working position in the pitman, the obstruction thus presented to the descent of the guards 34: will shift them upwardly relative to the head 1, causing the springs 11 to lift or-support the rollers 31 while-the plate 29 with the pockets 30 descends and thrusts the rollers outwardly into engagement with the projections 33 on the'plates 32, as shown in Fig 4. The head 1 is thus clutched or locked to the stationary ways 2 in which it is guided, and the further downward movement thereof and of the die 3 is instantly arrested, pre venting injury to the finger of the operator.

' The further downward or advance movement of the wrist pin 8 being thus arrested, the continued rotation of the eccentric or crank pin 5 shifts the bearing piece 18 downward in the slotted strap head of the pitman, compressing the spring 20, as shown in Fig. 5. Upon the completion of the rotation of the eccentric or crank pin 5, the parts of the pits man and the head 1. with the die 3, are returned to their initial. positions, as shown in I Figs. 1, 2 and 3. If a box'ls improperly placed on the anvil in such aposition that it would be crushed or inj ired by the descent of the die 3, as indicated at 42in .Fig. 4, it will by engagement with eithorone of the guards, operate the clutches and arrest the descent of the head 1 with the d e 3, as above eX-, pla .ied, and thereby prevent spoiling or mutilating the box. The spring 20, which is made of suiiicient strength to overcome the inertia of the-head 1 and friction between it and the ways 2, prevents the shoulder 22 on the stem 19 from being shifted in the p-itman out of position for engagement with the latch 23 when the latter is thrtst inwardly by the engagement of the projection 26 on lever 24 with the abutment 27, and thus enables the maohine to be operated with greater rapidity than would be possible w; thout such a spring.

Various modifications in the details of construction and arrangement of parts may be made in the adaptation of the safety devices to difl'erent machines for various kinds of work, without departure from the principle of the invention as. defined in the following claims.

I claim:

1. In a press or the like having a reciprocating part and an eccentric for actuating said part the combination of a pitman connecting the eccentric with said reciprocating part and having a bearing guided and movable in one end thereof toward and from the other end, a latch guided in the pitman transversely to its length and adapt ed to lock said bearing in its normal working position, a cam lever fulcrumed to and extending lengthwise of the pitman and having a yielding connection with the larch, a spring tending to hold the latch out of operative position, andan abutment 1n the latch into operative position when said reciprocating part reaches a certain point in its advance movement.

p 2. In a. press or the like having a reciprocating part and an eccentric for actuating said part the combination of a pitman connecting the eccentric with said reciprocating part and having at one end a bearing guided and movable lengthwise of the pitman, a

spring tending to hold said bearing in its normal Working posltion in the pitman, a

1 latch guided in the'pitman transversely to point in the advance of said reciprocating part.

3. In a press or the like having a reciprocating part and an eccentric for actuating the'same, the combination of a pitman connecting the eccentric with said reciprocating part and having a yielding bearing at one end, means adapted to lock said bearing in its normal working position at a certain point in the advance movement of said reciprocating part, a guard movably connected with said reciprocating part, and means operated by said guard to arrest the advance of said'reciprocating part when the guard meets an obstruction.

4. In a press or the like having a reciprocating part and an eccentric for actuating the same, the combination of a pitman connecting the eccentric with said reciprocating part and having a yielding bearing at one end, a guard movably connected with said reciprocating part, and means operated by said guard to arrest the advance of said 46 member carried by the head and adapted by I engagement with a stationary part of the 'machine to arrest'the advance of the head,

and a guard movably connected with the head and adapted when it meets an obstruction to shift the movable clutch member into operative position. 60

6. In a press or the like having a reciprocating head and an eccentric for actuating the same the combination of a pitman connecting the eccentric with said head and having a longitudinally yielding connection 66 with one of the connected parts, a clutch comprising a pocket having a rearwardly and outwardly inclined wall carried by the head, a roller loosely confined in said pocket and a stationary abutment adjacent to the 70 path of the roller, a guard movably connected with the head and adapted to thrust said roller backward in its pocket against the inclined Well thereof into positionl to engage with said abutment and to arrest the 76 advance of the head when the guard meets an obstruction.

In witness whereof I hereto affix my sig nature in presence of two witnesses.

FRIEDRICH GRAFFENBERGER.

Witnesses:

CHAS. L. Goss, CHAS. Eoennss.

pitman con- 50 

